Speed-changing mechanism.



A. R. MGGAUSLAND- SPEED CHANGING MECHANISM.

APPLICATION FILED APR. 2, 1909.

Patented Nov. 7, 1911.

v. 7 3 I k 1 1M Lmi WITN ESSES.

INVENTOR MKJCCFW 4 PM W COLUMBIA PLANOGRAPH (20., WASHINGTON. H r.

ARTHUR R. MOOAUSLAND, OF WASHINGTON, PENNSYLVANIA.

SPEED-CHANGING MECHANISM.

rooaoas.

Specification of Letters Patent.

Patented Nov. 7, 1911.

Application filed April 2, 1909. Serial No. 487,528.

To all whom it may concern."

Be it known that I, ARTHUR R. MCCAUS- LAND, a resident of Washington, inthe county of Washington and State of Penn sylvania, have invented a newand useful Improvement in Speed-Changing Mechanism; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof.

My invention relates to reversing mechanism for engines and has specialapplication to heat and air engines, notably gas engines, where it isnecessary to employ a suitable fly or balance wheel to insure the idleand compression strokes of the piston, and therefore, a matter of greatdifficulty to provide for the reversal of the stroke.

By my invention means are provided for the reversal of the engine whilemaintaining the revolution of the fly or balance wheel.

It consists, generally stated, in the employment of two independentshafts connected to the engine piston, one carrying the fly wheel andthe other driving connec tions, with means for reversing the stroke ofthe latter, or power shaft, without reversing the stroke of the flywheel shaft.

It also comprises certain specific improvements, as hereinafter setforth and claimed.

In the accompanying drawings Figure 1 is a side view illustrating myinvention. Fig. 2 is a plan view, Fig. 3 is a detail view partly insection illustrating a novel feature of my invention. Fig. 4 is aperspective view similar to Fig. 3; and Fig. 5 is a vertical section onthe line 5-5, Fig. 3. Fig. 6 is a vertical detail View; and Fig. 7 is adetail in perspective.

As the invention is illustrated in the drawing, any suitable engine isrepresented by the cylinder 1 attached to the bed frame 2. It has thepiston 3 and the cross-head 4 moving in suitable guides 5. The showingof the engine is intended to be diagrammatic only and to represent anysuitable type. Mounted in the bearing 6 of the bed frame is the flywheel shaft 7 carrying the fly wheel 8, the shaft 7 being illustrated asa crank shaft connected by the double pitmen 9 and 9 to the cross-head 4which is preferably journaled in an upwardly extending bearing in saidcross-head. On a lower level than the shaft 7 is the bearing 10, inwhich is mounted the driven or power shaft 11, which is also illustratedas a crank shaft having the crank 12 pivoted at 12 to the connecting rod13, which is also pivoted to the depending bifurcated arms 14 of thecross-head. The crank shaft is provided with suitable power connections,such, for example, as the driven wheel shown as a belt wheel 15 looselymounted on said shaft, which is provided with the clutch 16 to connectthe belt wheel with the shaft. The belt wheel is also shown providedwith the fly wheel 17 fixed to its rim.

The cross-head 4 is of novel construction. It is joined to the pistonrod 3 by the key 18, and has the lugs 4 sliding in the crosshead guides5. The piston rod 3 extends through the cross-head proper 4, and hasjournaled thereon the yoke member 19 having the bearing face 20 bearingagainst the cross-head proper 4, and the bearing face 21, flush with thewasher 22, which is held in place by the nut 23 screwed on the end ofthe piston rod. The inner faces 24 and 25 of the U-shaped yoke member 19are of a curved or corrugated surface, as shown clearly in Figs. 3 and4. These curved inner faces are in function cams which play on thecorresponding faces 26 and 27 of the bifurcated depending arm 14, asillustrated in Figs. 3, 4 and 6. This arm 14 is fixed as regardsrotation around the axis of the piston rod 3, as it is providedpreferably with the tongues 14 sliding in the cross-head guides 5.Attached preferably to the engine cylinder 1 is the switch member 29 sosituated. as to extend horizontally just above the line of travel of thecross head 4. This member 29 is preferably braced by the bracket 45fastened to the cross head guides 5. The member 29 is provided with theslot or guide 30 parallel to and preferably perpendicularly above theaxis of the piston rod 3. It has also the like slot 31 which convergesat an acute angle with the slot 30 joining it at the end 32. Attached tothe member 29 by the pivot 33 is the switch point 34 having the sleeveportion 35 provided with a finger 36 in engagement with the spring 37also attached to the member 29. The switch point 34 has also the stud 38at the pivot 33 having the lever arm 39 to which is attached the wire orcord 40, as shown clearly in (Fig. 2). Attached to the yoke member 1.9is the pin 41 which is normally in register with the slot 30 of themember 29.

The shaft 7 to which is attached the fly wheel 8 has, as mentionedabove, the dual pitmen 9 and 9 connecting it to the crosshead 4. Thesepitmen are journaled on the pivot 42 provided with the key 43, so that pis increased.

where, for a period, it is not desired to use the reversing mechanism,the pivot 42 may be withdrawn and the pitmen removed.

During normal operations the clutch 16 is set and the pin 41 travels inthe slot 30 backward and forward at each complete stroke of the piston3, being adjusted so as to travel in the forward stroke nearly to theend 32 of the slot 30. \Vhen it is desired to reverse the powerconnections or driven parts the clutch 16 is unset and the cord 40 isdrawn so as to press the switch point 34 into the slot 30. The switchpoint 34 will be forced against this maintained pressure temporarilyback into its normal position by the pin 41 on the forward stroke of theengine, until the pin passes the switch point, unless indeed, thepressure is exerted just at the instant of the extreme forward position.In either case the switch point 34 will, within the period of one fullor double stroke, be forced across the slot 30 so that on thecommencement of the return or backward stroke the pin 41 will be forcedto travel along the converging slot 31. This will gradually turn therotary yoke member 19, and therefore by the joint action of the cambearing faces 24 and 26, and 25 and 27, on the yoke member 19 and on thedepending arm 14 respectively, force the depending arm longitudinally ofthe piston rod 3. This operation is clearly illustrated in Figs. 3 and 4taken together; as the corrugated cam faces are so arranged and theslots 30 and 31 will be so adjusted as, when the back stroke of thepiston is completed and, therefore, when the pin 41 has reached itsextreme backward position in the slot 31, to force the depending arm- 14to its extreme forward position relative to the piston rod 3, the. camfaces being then at their extreme phase of juxtaposition. By this meansthe distance taken parallel to the axis of the piston rod 3 between anygiven point on the crosshead proper 4 and the pivot 12 That is to say,the crank 12 is kept farther away from the crosshead 4, or retarded inits stroke from its normal position therein. This results, therefore, in

making impossible the passage of the connecting rod 13 past the deadcenter, or extreme backward phase of the piston stroke. The fiy wheel 8and its pitmen 9 and 9 are entirely unaffected by this operation,however, and maintain the engine in its regular cycle of operation. I

The connecting rod 13 and the power shaft 11 are therefore forcedbackward and their direction reversed. This is accomplished withoutgreat jar or tendency to wrench the machinery, as the fly Wheel 17together with the driven parts and the belt wheel 15 have already beenloosened on the shaft 11, and the moment-um of the connecting rod 13,the crank 12 and rotating shaft 11 alone remain to be overcome. As soonas the direction of the connecting rod 13 is reversed the clutch isimmediately re-set and the pressure withdrawn from the cord 40, whichallows the spring 37 to press the switch point 34 into its normalposition as soon as the pin 41 has passed into its extreme forwardposition beyond the switch point 34. By this means the direction justobtained is automatically maintained. To reverse and obtain the originaldirection of rotation the operation is identical with that outlinedabove.

It will be noticed that a comparatively slight movement of the arm 14relative to the normal position of the crosshead will result in stoppingthe crank 12 a comparatively much greater distance before it has reachedits dead center, or horizontal position. This is because, as is wellunderstood to those skilled in the art, a distance along a diameter of acircle extending to a point will result in a much greater distance alongits circumference from the intersection of that diameter with thecircumference to the intersection of a perpendicular from that point onthe diameter to the circumference. For this reason likelihood of jammingthe machinery is obviated.

My invention is particularly adapted to oil well and like machinerywhere the reversal of the driven parts is only occasionally required,and where it is sometimes desirable to disconnect the reversingmechanism entirely. This can be done as outlined above, in connectionwith the removable pitmen 9 and 9. In this type of machinery theoperator is frequently at a distance from the reversing mechanism,whichcontingency is provided for as outlined above. Vhilc particularlyadapted to this type of machinery I regard my invention as broadly newand claim for it all uses to which it is applicable.

What I claim is:

1. In speed changing mechanism a reciprocating dri ing member, a powershaft, a driving connection between said shaft and said driving member,a driven wheel, and a clutch adapted to fix it to said shaft, and meansfor shortening said driving connection and thereby cooperating with saidclutch to reverse said driven wheel.

2. In speed changing mechanism, an engine piston, two separate rotaryshafts, two connecting rods pivotally connected to said piston and toeach of said shafts respectively, one of said shafts being provided witha fly wheel and the other with a suitable power connection, and meanscooperating therewith to reverse said power connection while maintainingthe direct-ion of rotation of said fly wheel.

3. In speed changing mechanism a driving member, a rotary driven member,a connection between said driving and driven members including aconnecting rod and an arm pivoted to said rod and connected to saiddriving member, clutching means on said driven member, and means forvarying the length of said connection to reverse the driven member.

4. In speed changing mechanism, in combination with an engine providedwith a piston, crosshead and crosshead guides, a fly wheel and pitmanconnected to said crosshead, and a power shaft, a connection betweensaid power shaft and said engine including a connecting rod and crank,and an arm pivoted to said connecting rod and connected to saidcrosshead, and mechanism for moving said arm longitudinally of saidcrosshead.

5. In speed changing mechanism, an engine provided with a piston andcrosshead, in combination with a power shaft, a connecting rod connectedthereto, and a fixed member provided with converging slots, saidcrosshead being provided with a rotatable yoke member having a collarprovided with a cam face, said yoke member having a pin normally slidingin one of said slots, switching means adapted to direct said pin intothe other of said slots and thereby partially rotate said yoke member,an arm pivoted to said connecting rod and provided with a cam portion inengagement with said cam face of said yoke member, whereby on theturning of the yoke member the said pivoted arm will be movedlongitudinally of the crosshead.

6. In speed changing mechanism, an engine provided with a piston rod andcrosshead, a crank and connecting rod connected to said power shaft, anda fixed member provided with two converging slots, one of which isparallel with the piston, said crosshead being provided with a yokemember journaled around said piston axis having two collars providedwith curved corrugated inner cam faces, and with a pin normally slidingin register with said slot parallel to said piston axis, a switch andactuating means therefor adapted to direct said pin into the nonparallelslot and thereby partially rotate said yoke member, and a bifurcated armpivoted to said connecting rod provided with corrugated cam facesengaging said cam faces of said yoke member whereby in the turning ofthe yoke member the said pivoted arm will be forced longitudinally ofthe crosshead.

7. In speed changing mechanism, an engine having a piston, a rotaryshaft pro vided with a fly wheel and connected to said engine, aseparate power shaft provided with a driven wheel journaled thereon, anda clutch adapted to fix it thereto, and mechanism connecting said powershaft and said engine, including a connecting rod and an arm pivotedthereto connected to the engine piston, and means for moving said armlongitudinally of said piston.

8. In speed changing mechanism, an engine, a rotary shaft provided witha fly wheel and connected to said engine, a separate power shaftprovided with a driven wheel journaled thereon, and a clutch adapted tofix it thereto, and mechanism connecting said power shaft and saidengine including a pivoted arm connected to the engine crosshead, and afixed member rigid with the engine body, and turning means cooperatingwith said mentioned mechanism adapted to change the length of saidconnecting mechanism and reverse the engine stroke.

9. In speed changing mechanism, two separate shafts, one of which isprovided with a fly wheel and the other with power connections, adriving member separately con nected to both shafts, the connection tothe power shaft including a member rotatable on the driving axis andhaving a cam face, and a member fixed relative to the driving axis andhaving a cam face in engagement with the aforesaid cam face.

10. In speed changing mechanism, a fixed member provided with connectingslots, .a reciprocating member provided with a cam face and a memberreciprocating identically with said reciprocating member provided with acam face engaging with said cam face, and provided with means inengagement with said slots, whereby said cam faces are relatively moved.

11. In speed changing mechanism, a fixed member provided with connectingslots, a

reciprocating driving member, a member reciprocating identicallytherewith and provided with means in engagement with said slots, adriven member, and means cooperating therewith to reverse said drivenmember.

12. In speed changing mechanism a reciprocating driving member, a drivenshaft, a driving connection between said shaft and said driving member,means for lengthening said driving connection and thereby reversing itsdirection and the direction of the rotation of the driven shaft, andmeans for restoring the original length of driving connection at thenext stroke of the piston and thereby maintaining the driven shaft inits reverse direction.

In testimony whereof, I the said ARTHUR R. MoOAUsLANn have hereunto setmy hand.

ARTHUR R. MCCAUSLAND.

Witnesses:

J. F. DONEHOO, J. G. BRYANT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

